So YPAQ was accurate and not faulty, good to know it was not error prone.

It is error prone but never 4 at once. That and I couldn't get it to sound right.During the last YPAO, the center was out. I hadn't changed the wiring or the speaker when installing the amp.Not really a concern with one channel, its done it countless times before but never on multiple attempts or with more than one channel.